JP6809044B2 - Plastic bottles and fillers - Google Patents

Description

The present invention relates to plastic bottles and fillers, and more specifically to the structure of lightweight plastic bottles and fillers.

Plastic bottles, especially PET (PolyEthylene Terephthalate) bottles, are often used as containers for filling beverages and the like. The market size of large PET bottles is expanding due to the demand for stockpiling and the influence of diversification of daily life. However, the weight of a large PET bottle increases due to the large capacity of the filled contents, and the waist circumference becomes large, which makes it difficult to hold the bottle.

In Patent Document 1, a waist portion having a reduced body diameter is formed at a predetermined height position of the body portion, and the waist portion is periodically connected in the circumferential direction to form a wavy convex portion. , A synthetic resin round bottle characterized in that a recess for a finger hook is formed is disclosed.

JP-A-2015-160656

According to the synthetic resin round bottle of Patent Document 1, even if the contents are fully filled with a large-capacity bottle and the contents are heavy, the bottle can be gripped more stably and the bottle can be held with one hand. It is said that the contents can be more easily poured out from the mouthpiece by tilting the bottle while it is lifted and carried. Further, according to the synthetic resin round bottle of Patent Document 1, a plurality of wavy convex portions provided periodically function as a support column for supporting the bottle, and the rigidity and buckling strength of the bottle are increased. It is said that it can be held at the level.

In the synthetic resin round bottle of Patent Document 1, the fingertip of the first finger is hung on the recess of the waist portion on the front side of the bottle, and the second or third finger is hung on the recess of the waist portion on the back side. A hand from the fingertips of the first finger to the fingertips of the other fingers by bringing the other fingers, the third finger, the fourth finger and the fifth finger, or the second finger, the fourth finger and the fifth finger into contact with the body. It is said that the body of the bottle can be firmly gripped as a whole. However, in this configuration, the fingers protruding from the waist grab the body with a larger body diameter and the boundary between the waist and the body, and the shape of the bottle and the fingers do not match exactly. It is difficult to grip the bottle body. On the other hand, in a structure in which the waist portion is extended in the height direction, this portion serves as a bending point, and the buckling strength of the synthetic resin round bottle is reduced.

Furthermore, in recent years, efforts have been made to reduce the weight of PET bottles by reducing the amount of raw materials used from the viewpoints of resource saving and reduction of environmental load during transportation. Then, the lighter the PET bottle, the thinner the wall thickness, and the stronger the PET bottle tends to be. Therefore, the lighter the PET bottle, the more stringent the conditions for maintaining its strength. However, Patent Document 1 does not describe the weight reduction of the PET bottle 1.

By the way, PET bottles include a cylindrical round PET bottle and a square tubular PET bottle. Compared to round PET bottles, square PET bottles have the same width and can have a larger internal volume, are superior in loading efficiency, display efficiency, and storage efficiency during distribution and storage, and can be attached to containers. It has the advantage that the label is easy to see. On the other hand, the square PET bottle tends to be more difficult to hold than the round PET bottle due to the difference in distance between the diagonal direction and the facing direction and the difference in hardness at each position. However, the difference in shape may affect the purchasing motivation, and improving the ease of holding a square PET bottle is not as simple as changing the shape to a round PET bottle. The configuration described in Patent Document 1 is a round bottle, and Patent Document 1 does not describe or suggest a square bottle having various advantages.

Therefore, an object of the present invention is to provide a large and square plastic bottle and a filler which have both light weight and high strength against an external force and are easy to hold.

In order to solve the above problems, the present invention relates to a plastic bottle having a mouth portion, a shoulder portion, a body portion, and a bottom portion sequentially in the axial direction, in which the body portions are adjacent to a plurality of wall portions and in the circumferential direction. The cylindrical portion has a square tubular portion formed of a corner portion connecting the matching wall portions, and a cylindrical portion having the square tubular portion divided in the axial direction and having a circular cross section orthogonal to the axial direction . It has a constricted portion that is narrowed in the radial direction, the constricted portion has a rib that is convex outward in the radial direction and extends in the axial direction, and the rib is formed in any said cross section of the constricted portion. the diameter is configured so that the distance from the center direction is maximum, the constriction is characterized Rukoto to have a panel to the ribs adjacent opposite side.

Further, the constriction portion has an upper side curved toward the upper side and a lower side curved toward the lower side, and the panel has the rib, the upper side, and the lower side. formed from and wherein Rukoto.

Further, the panel is characterized by being composed of an even number.

Further, the maximum body diameter of the cylindrical portion is the same as the facing distance of the square tubular portion.

Further, the square tubular portion and the cylindrical portion are connected via a connecting groove that is recessed in the radial direction and extends in the circumferential direction.

Further, the rib is characterized by having a twist in the circumferential direction.

Further, the constricted portion is characterized in that the distance in the axial direction is 55 mm or more and 85 mm or less.

Further, the internal volume of the plastic bottle is 680 ml or more and 2500 ml or less.

Further, the filler according to the present invention is characterized by being composed of the above-mentioned plastic bottle and the liquid to be filled.

According to the present invention, in a plastic bottle having a mouth portion, a shoulder portion, a body portion, and a bottom portion sequentially in the axial direction, the body portion is a corner connecting a plurality of wall portions and adjacent wall portions in the circumferential direction. It has a square tube part composed of parts and a cylindrical part having a circular cross section orthogonal to the axial direction by dividing the square tube part in the axial direction, and the cylindrical part has a constricted part narrowed in the radial direction. However, the constriction has ribs that are convex outward in the radial direction and extend in the axial direction, and the ribs are configured so that the distance from the center in the radial direction is maximized in any cross section of the constriction. parts can provide Runode, and lightweight, and has both a high strength against an external force, and a rectangular plastic bottle with easy large, it has to have a panel for the adjacent ribs with opposite side.

Further, the constricted portion has a top side which is curved toward the upper side, and the lower side is curved toward the lower, the panel is that is formed with a rib, and the upper side, from a lower side, According to the configuration, it is possible to provide a large and square plastic bottle that has both light weight and higher strength against external force and is easier to hold.

Further, since the panel is composed of an even number, it is possible to provide a large and square plastic bottle which has both light weight and high strength against an external force and is easier to hold.

Further, according to the configuration in which the maximum body diameter of the cylindrical portion is the same as the facing distance of the square tubular portion, it has both light weight and higher strength against external force, and is a large and square shape that is easier to hold. Plastic bottles can be provided.

Further, according to the configuration in which the square tube portion and the cylindrical portion are connected via a connecting groove that is recessed in the radial direction and extends in the circumferential direction, both light weight and higher strength against external force are achieved. We can provide large, square plastic bottles that are easy to hold.

Further, the ribs can provide a large, square plastic bottle that is both lightweight and has higher strength against external forces and is easier to hold, due to the configuration having a twist in the circumferential direction.

Furthermore, according to the configuration in which the axial distance is 55 mm or more and 85 mm or less, the constricted portion is a large, square plastic that has both light weight and higher strength against external force and is easier to hold. Bottles can be provided.

Further, according to the configuration in which the internal volume of the plastic bottle is 680 ml or more and 2500 ml or less, it is possible to provide a large and square plastic bottle that has both light weight and high strength against external force and is easy to hold. Can be done.

Further, since the filler according to the present invention is composed of the above-mentioned plastic bottle and the liquid to be filled, it has both light weight and high strength against external force, and is a large and square plastic that is easy to hold. Fillers in which bottles are used can be provided.

It is a front view which showed the PET bottle as an example of the plastic bottle which concerns on this embodiment. It is a top view of a PET bottle. It is a bottom view of a PET bottle. It is an enlarged front view of the bottom of a PET bottle. It is a front view which showed the PET bottle which concerns on the modification. It is a front view of the PET bottle of Comparative Example 1 and Comparative Example 2.

The details of the embodiment of the present invention will be described below with reference to the drawings. First, the configuration of the plastic bottle according to the present embodiment will be described in detail. FIG. 1 is a front view showing a PET bottle 1 as an example of a plastic bottle according to the present embodiment, and FIG. 2 is a top view of the PET bottle 1. The PET bottle 1 has a mouth portion 10, a shoulder portion 20, a body portion 30, and a bottom portion 40 in order in the axial direction thereof. The illustrated PET bottle 1 is a so-called square bottle having a substantially square cylinder shape having a plurality of wall portions 31 and a corner portion 32 connecting adjacent wall portions 31 in the circumferential direction of the PET bottle 1 to the body portion 30. is there.

In the following, for convenience of explanation, the mouth portion 10 in which the contents are filled into the container in the state of FIG. 1 which is upright so that the axial direction of the PET bottle 1 extends vertically is set upward. The PET bottle 1 is formed to have a total height H1 from the bottom 40 to the mouth 10.

The mouth portion 10 serves as a filling port and a spout for the contents, and the PET bottle 1 is sealed by attaching a lid (not shown) to the mouth portion 10. The mouth portion 10 may be crystallized until it is colored white by heating with a so-called crystallizing device so as to have the heat resistance required for filling the contents at a high temperature.

The upper side of the shoulder portion 20 is connected to the mouth portion 10, while the lower side thereof is connected to the body portion 30. The shoulder portion 20 is formed in a pyramid base cylinder shape that extends in the radial direction of the PET bottle 1 from the upper side to the lower side in the axial direction.

The PET bottle 1 has a ridge line 21 extending in the circumferential direction between the shoulder portion 20 and the body portion 30. The ridge line 21 has a function of absorbing the axial load of the PET bottle 1. The ridge line 21 undulates in the axial direction and is located closest to the body portion 30 in the corner portion 32. The shoulder portion 20 in the region above the corner portion 32 is likely to be bent by an axial load as it is. However, due to the configuration in which the ridge line 21 is located on the side of the body portion 30 most in the corner portion 32, the load is dispersed without being concentrated on the portion that is easily bent, and the buckling strength of the PET bottle 1 is increased.

A plurality of flat plate-shaped cut surfaces are formed on the shoulder portion 20. Then, the side serving as the boundary of these cut surfaces mainly extends in the axial direction, and thus functions as a support column for the load in the axial direction of the PET bottle 1.

On the wall portion 31, an isosceles triangular region long in the axial direction with the ridge line 21 as the base is formed by the ridge line 22 protruding toward the outside of the PET bottle 1. Further, inside the isosceles triangle region, three triangular panels are formed by three ridges 23 protruding inward of the PET bottle 1. By constructing the shoulder portion 20 in the region above the wall portion 31 in this manner, the strength against the axial and radial loads of the PET bottle 1 is increased, and the pressure inside the PET bottle 1 is changed. Its shape is maintained without being distorted.

Further, the shoulder portion 20 has a ridge line 24 that protrudes toward the outside of the PET bottle 1 and extends axially from the center in the circumferential direction at the corner portion 32. The ridge line 24 tends to be dented inside the PET bottle 1 when pressed. Further, a ridge line 25 protruding toward the outside of the PET bottle 1 is also formed between the side of the mouth portion 10 of the ridge line 24 and the boundary between the wall portion 31 and the corner portion 32 of the ridge line 21. Therefore, a fan-shaped sinking panel 26 having a ridge line 24 that divides the central angle into two is formed on the shoulder portion 20 in the region above the corner portion 32. The ridge line 25 prevents the deformation when the ridge line 24 is pressed from spreading to the region outside the fan shape.

A label such as a shrink label or a roll label on which information on the contents of the PET bottle 1 and a pattern for enhancing the design is printed is packaged in the body portion 30. A biaxially stretched polystyrene film or the like having good heat shrinkage is used for the shrink label attached by heat shrinkage. Since the shrink label is made of a different material from the PET bottle 1, it is separated when it is recycled after the PET bottle 1 is used. Since the shrink label is mainly attached by being hooked on the corner portion 32, it becomes easy to peel off by removing the catch on the corner portion 32. When the ridge line 24 is pressed, a gap is formed between the PET bottle 1 and the label near the corner portion 32, which makes it easier to grasp the label and partially removes the catch of the corner portion 32, so that the label can be easily peeled off. be able to.

The plurality of cut surfaces formed on the shoulder portion 20 illustrated in FIG. 1 and the like are formed in a flat plate shape, and are not curved to the outside or the inside of the PET bottle 1. However, if the shoulder portion 20, particularly the fan-shaped sinking panel 26, is configured to be curved outward from the PET bottle 1, a wider gap is created between the PET bottle 1 and the label, making the label easier. It can be peeled off.

Although the shoulder portion 20 is not limited to the above-described configuration, it is preferable that the shoulder portion 20 has a ridge line 21 and a ridge line 24 in terms of the strength and shape maintenance function of the PET bottle 1, the ease of peeling off the label, and the like.

The body portion 30 has an upper square cylinder portion 50u and a lower square cylinder portion 50d as a square cylinder portion including a wall portion 31 and a corner portion 32, an upper square cylinder portion 50u, and a lower square cylinder portion 50d as axes. It has a cylindrical portion 60 having a circular cross section that is divided in the direction and orthogonal to the axial direction.

FIG. 3 is a bottom view of the PET bottle 1. The upper square tube portion 50u and the lower square tube portion 50d illustrated in FIGS. 1, 2, and 3 each have four wall portions 31 and four corner portions 32 having the same shape as each other. doing. The corner portion 32 is curved outward in the radial direction. Both the upper square cylinder portion 50u and the lower square cylinder portion 50d have the same radial dimensions at the top and bottom, and have a substantially regular square cylinder shape as a whole. The upper square cylinder portion 50u and the lower square cylinder portion 50d have a shape close to a cylinder by having the corner portion 32 curved outward, and the buckling strength thereof is improved.

Both the upper square cylinder portion 50u and the lower square cylinder portion 50d are configured to have a diagonal distance D1 and a facing distance D2. The diagonal distance D1 is larger than the face-to-face distance D2. The diagonal distance D1 is, for example, 84.5 mm, and the face-to-face distance D2 is, for example, 77.1 mm. By forming the facing distance D2 of the upper square cylinder portion 50u and the lower square cylinder portion 50d to be the same, each wall portion 31 of the upper square cylinder portion 50u and the lower square cylinder portion 50d becomes a grounding portion. The PET bottle 1 can be stably placed in a horizontal orientation with a horizontal axial direction.

The upper square tube portion 50u and the lower square tube portion 50d have a plurality of annular peripheral grooves 51 that are recessed inward in the radial direction and cross the wall portion 31 and the corner portion 32 in the circumferential direction. The peripheral groove 51 has a substantially rounded square cross-sectional shape in the horizontal direction, and has a substantially tapered shape having a flat bottom surface in the vertical cross-sectional shape. However, the shape of the vertical cross section of the peripheral groove 51 may be arcuate or V-shaped. The peripheral groove 51 has a function of increasing the side wall strength, which is the strength to withstand a load in the radial direction. Then, by increasing the side wall strength of the upper square cylinder portion 50u, the ease of attaching the label to the upper square cylinder portion 50u is improved. Further, the peripheral groove 51 acts as a cushion against a load in the axial direction, and has a function of preventing buckling of the body portion 30.

The depth of the peripheral groove 51 is substantially constant in the wall portion 31. On the other hand, in the corner portion 32, the peripheral groove 51 is formed so that the depth is minimized at the center in the circumferential direction. The depth of the peripheral groove 51 is different between the wall portion 31 and the corner portion 32, and the depth at the wall portion 31 is larger than that at the corner portion 32.

The peripheral groove 51 configured in this way has a function of increasing the side wall strength at the wall portion 31 and preventing buckling with respect to an axial load, and reducing the amount of compressive deformation with respect to an axial load at the corner portion 32. Has. Since the side wall strength is increased at the wall portion 31, the PET bottle 1 can be stably loaded sideways. The peripheral groove 51 has a function of preventing the load from being concentrated on the corner portion 32 and increasing the buckling strength of the body portion 30. Further, since the peripheral groove 51 has a small depth at the corner portion 32 which is a distance from the center of the PET bottle 1 in the radial direction, the shape is not severely uneven and the shapeability is good.

The peripheral groove 51 may be formed with a constant width in the circumferential direction, but is formed so that the width at the center of the wall portion 31 in the circumferential direction is maximized. If the width of the peripheral groove 51 is too large, the strength against a load in the axial direction decreases and the amount of compressive deformation increases. Therefore, the peripheral groove 51 has a larger width at the wall portion 31 than at the corner portion 32. The peripheral groove 51 has a function of increasing the rigidity of the body portion 30 by being configured in this way. Further, since the peripheral groove 51 has a large width at the wall portion 31 having a large depth, it does not have a shape with severe irregularities and has good shapeability.

The upper square cylinder portion 50u is formed with four peripheral grooves 51a, 51b, 51c, and 51d in this order from the upper side in the axial direction. Two peripheral grooves 51e and 51f are formed in the lower square cylinder portion 50d in order from the upper side in the axial direction. The peripheral groove 51 is composed of three types having different depth and width dimensions. The peripheral groove 51a and the peripheral groove 51f, the peripheral groove 51b and the peripheral groove 51c, and the peripheral groove 51d and the peripheral groove 51e have the same dimensions, respectively. The depth of the peripheral groove 51 is set to peripheral groove 51d> peripheral groove 51a> peripheral groove 51b, and the width of the peripheral groove 51 is set to peripheral groove 51d> peripheral groove 51a> peripheral groove 51b.

The peripheral groove 51a and the peripheral groove 51d increase the side wall strength of the upper square tubular portion 50u not only in the vicinity of each groove but also in the region between the peripheral groove 51a and the peripheral groove 51d. Therefore, the depth and width dimensions of the peripheral groove 51b and the peripheral groove 51c can be reduced. Since the unevenness of the upper square cylinder portion 50u is suppressed, for example, the appearance defect when the shrink label is attached is less likely to occur, and the manufacturing efficiency and the display effect (advertising effect) of the label can be improved.

Here, four peripheral grooves 51a, 51b, 51c, and 51d are formed in the upper square tube portion 50u, and two peripheral grooves 51e and 51f are formed in the lower square tube portion 50d. An example is shown. However, the number thereof is not particularly limited, and is appropriately designed depending on the vertical width of the upper square cylinder portion 50u and the lower square cylinder portion 50d, the depth and width of the groove, and the like. Further, the depths and widths of all the peripheral grooves 51 may be designed to be the same.

The cylindrical portion 60 has a constricted portion 61. The constricted portion 61 is formed by narrowing the body portion 30 in the radial direction. The constricted portion 61 has a short waist circumference and is easy to grip. Therefore, the constricted portion 61 functions as a grip portion, and the PET bottle 1 can be easily held.

The constricted portion 61 has a rib 62 extending in the axial direction. The rib 62 projects toward the outside of the PET bottle 1. The rib 62 has a function as a support for both the axial and radial loads of the PET bottle 1. A plurality of ribs 62 are arranged in the circumferential direction of the constricted portion 61. The constricted portion 61 in which the plurality of ribs 62 are arranged has improved strength and is less likely to be deformed, so that the PET bottle 1 can be easily held. Further, the rib 62 can be hooked on the gripped finger to make it easier to hold the PET bottle 1.

At the upper end of the constricted portion 61, adjacent ribs 62 are connected by an upper side 63. The upper side 63 is curved in an arc shape toward the upper side. Similarly, at the lower end of the constricted portion 61, adjacent ribs 62 are connected by a lower side 64. The lower side 64 is curved in an arc shape toward the lower side. By forming the upper side 63 and the lower side 64, the cylindrical portion 60 is less likely to be deformed, and the PET bottle 1 can be easily held. Further, the curved upper side 63 and lower side 64 can absorb the axial load of the PET bottle 1 and increase the buckling strength. The two adjacent ribs 62 are opposite sides, and the opposite side, the upper side 63, and the lower side 64 form an oval panel 65. Therefore, the constricted portion 61 is formed in a tubular shape in which a plurality of panels 65 curved inward in the radial direction are connected in the circumferential direction.

The region above the upper side 63 and the region below the lower side 64 are cylindrical with the same upper and lower diameters.

The panel 65 including the rib 62 has a curved surface shape so as to reduce the diameter toward the center in the axial direction starting from the upper side 63 and the lower side 64. The rib 62 is configured so that the distance from the center in the radial direction is maximized in an arbitrary cross section orthogonal to the axial direction of the constricted portion 61. That is, the cross section of the constricted portion 61 is a polygon with the rib 62 as the apex. The PET bottle 1 configured in this way has both light weight and high strength against an external force, and is easy to hold.

The side of the polygon formed in the cross section of the constricted portion 61 may be a curved line curved inward in the radial direction, a straight line, or a curved line curved outward. It may be in the shape. However, if the side of the cross section of the constricted portion 61 is curved inward, the PET bottle 1 becomes easier to hold.

As illustrated in FIG. 1 and the like, the rib 62 preferably has a twist in the circumferential direction. Since the rib 62 has a twist, it is more easily applied to the gripped finger, and the PET bottle 1 is more easily held. Further, since the rib 62 has a twist, the load in the axial direction is dispersed in the circumferential direction, and the buckling strength of the PET bottle 1 can be increased.

The rib 62 has an inclination of an angle θt with respect to the vertical line L. If the angle θt is too large, the function of the rib 62 as a support is diminished. Therefore, the angle θt is preferably 0 ° or more and 60 ° or less from the viewpoint of maintaining the strength of the PET bottle 1 while maintaining the ease of holding. Further, from the viewpoint of further improving the ease of holding, the angle θt is more preferably 20 ° or more and 40 ° or less. On the other hand, from the viewpoint of further improving the buckling strength, the angle θt is more preferably 0 ° or more and 35 ° or less.

The rib 62 may not be twisted and may be counterclockwise, but it may be easier to hold if it is clockwise as illustrated in FIG.

If the number of panels 65 is too small, the buckling strength of the PET bottle 1 tends to be insufficient. On the other hand, if the number of panels 65 is too large, the ease of holding the PET bottle 1 will decrease. Therefore, from the viewpoint of improving the ease of holding the PET bottle 1 while maintaining its strength, the number of panels 65 is preferably 5 or more and 12 or less, and more preferably 6 or more and 8 or less. The panel 65 of the PET bottle 1 illustrated in FIG. 1 and the like is composed of six panels.

When the panel 65 is composed of an odd number, the ribs 62 and the surfaces of the panel 65 face each other at both ends in the radial direction of the constricted portion 61. On the other hand, if the number of panels 65 is an even number, the surfaces of the panels 65 face each other. When the surfaces of the panels 65 face each other, the length of the constricted portion 61 in the radial direction becomes shorter and easier to hold. Therefore, the panel 65 is preferably composed of an even number.

It is preferable that the plurality of panels 65 have the same shape from the viewpoint of preventing the stress on the PET bottle 1 from being concentrated on a specific portion of the constricted portion 61 and reducing the ease of holding.

Further, if the lightness of the PET bottle 1 does not matter, the panel 65 may be divided into two in the axial direction.

The axial distance H2 of the constricted portion 61 is preferably designed based on the width of the hand from the second finger to the fifth finger. The PET bottle 1 can be held stably by covering the constricted portion 61 with the entire palm. If the axial distance H2 of the constricted portion 61 is too short, the finger protrudes from the constricted portion 61 and the ease of holding the PET bottle 1 decreases. On the other hand, if the axial distance H2 of the constricted portion 61 is too long, it becomes difficult to maintain the strength of the PET bottle 1. Therefore, from the viewpoint of maintaining the strength while maintaining the ease of holding the PET bottle 1, it is preferable that the axial distance H2 of the constricted portion 61 is 50 mm or more and 100 mm or less, and 55 mm or more and 85 mm or less. Is more preferable.

The PET bottle 1 is configured to have a sufficient axial distance H2 of the constricted portion 61. The constricted portion 61 configured in this way provides a strong clue to guide the user to be treated as a grip portion. Therefore, the PET bottle 1 is configured so that the constricted portion 61 can be handled as a grip portion without explanation.

If the ratio (H2 / H1) of the ratio of the axial distance H2 of the constricted portion 61 to the total height H1 of the PET bottle 1 is too small, the grip portion becomes small and the PET bottle 1 becomes difficult to hold. On the other hand, if H2 / H1 is too large, the upper square cylinder portion 50u becomes small and the area for displaying the label becomes narrow. Further, if H2 / H1 is too large, it becomes difficult to maintain the strength of the PET bottle 1. Therefore, it is preferable that the value (H2 / H1) of the ratio of the axial distance H2 of the constricted portion 61 to the total height H1 of the PET bottle 1 is 0.15 or more and 0.45 or less.

The constricted portion 61 is formed so that the diameter is narrowed so as to be the minimum cylinder diameter D4 with respect to the maximum cylinder diameter D3 having the same diameter as the cylindrical portion 60. When the PET bottle 1 is formed by blow molding, the constricted portion 61 can be made thicker by making the PET bottle 1 more inner in the radial direction. The thicker the constricted portion 61, the higher the strength, and the structure can be maintained. The wall thickness of the constricted portion 61 is preferably 0.15 mm or more and 0.50 mm or less.

The value (D4 / D3) of the ratio of the minimum body diameter D4 to the maximum body diameter D3 of the constricted portion 61 is preferably 0.65 or more and 0.95 or less, and is 0.70 or more and 0.85 or less. Is more preferable. With such a configuration, the ease of holding the PET bottle 1 can be improved and the buckling strength can be effectively increased. If the value (D4 / D3) of the ratio of the minimum body diameter D4 to the maximum body diameter D3 is too large, it becomes difficult to improve the ease of holding the PET bottle 1. On the other hand, if the value (D4 / D3) of the ratio of the minimum body diameter D4 to the maximum body diameter D3 is too small, the stress on the axial load of the PET bottle 1 is sufficiently concentrated in the vicinity of the minimum body diameter D4. No buckling strength can be obtained.

The PET bottle 1 is configured to have a constricted portion 61 having a narrowed diameter and a rib 62 extending in the axial direction so as to improve the ease of holding while ensuring sufficient buckling strength.

There is no limitation on the magnitude relationship between the maximum body diameter D3 of the constricted portion 61 and the facing distance D2 of the upper square cylinder portion 50u and the lower square cylinder portion 50d. However, from the viewpoint of loading efficiency of the PET bottle 1, the cylindrical portion 60 is preferably an inscribed circle of the upper square cylinder portion 50u and the lower square cylinder portion 50d. That is, it is preferable that the facing distance D2 and the maximum body diameter D3 have the same length.

The axial positions of the cylindrical portion 60 with respect to the upper square cylinder portion 50u and the lower square cylinder portion 50d are not limited to the configuration shown in FIG. 1 and the like. For example, the cylindrical portion 60 may be arranged on the upper side of the square tubular portion 50u from the position shown in FIG. 1 or the like. With this configuration, the area to which the label can be attached becomes smaller, but the contents can be more easily poured out.

It is preferable that the upper square cylinder portion 50u, the lower square cylinder portion 50d, and the cylindrical portion 60 are connected to each other via a connecting groove 70 that is recessed in the radial direction and extends in the circumferential direction, respectively. The articulated groove 70 and the articulated groove 75 have a function of receiving an axial load as a cushion and preventing bending of the articulated portion. Further, the articulated groove 70 and the articulated groove 75 have a function of increasing the side wall strength in the vicinity of the articulated portion. The articulated groove 70 and the articulated groove 75 have a circular cross-sectional shape in the horizontal direction and a substantially tapered shape having a flat bottom surface in the vertical cross-sectional shape. The articulated groove 70 and the articulated groove 75 may have an arc-shaped or V-shaped cross-sectional shape in the vertical direction.

If the depth of the connecting groove 70 and the connecting groove 75 is too shallow, it becomes difficult to increase the side wall strength. On the other hand, if the depth of the connecting groove 70 and the connecting groove 75 is too deep, the shapeability of the PET bottle 1 at the time of molding tends to decrease. The depth of the articulated groove 70 and the articulated groove 75 is preferably 0.005 or more and 0.07 or less, and more preferably 0.03, as a ratio value to the maximum body diameter D3.

If the width of the connecting groove 70 and the connecting groove 75 is too wide, it becomes difficult to increase the side wall strength. On the other hand, if the widths of the articulated groove 70 and the articulated groove 75 are too narrow, the shapeability of the PET bottle 1 at the time of molding tends to decrease. The width of the articulated groove 70 and the articulated groove 75 is preferably 0.5 or more and 5.0 or less as a ratio value to the depth of the articulated groove 70 and the articulated groove 75.

Since the inclination of the surface on the side of the upper square tube portion 50u of the connecting groove 70 and the side of the lower square tube portion 50d of the connecting groove 75 is uniform, it seems that this surface is just chamfered at the corner portion 32. It has a shape. Therefore, the load in the axial direction is dispersed without being concentrated on the corner portion 32 that is easily bent, and the buckling strength of the PET bottle 1 is increased.

FIG. 4 is an enlarged front view of the bottom 40 of the PET bottle 1. The bottom portion 40 is connected to the lower side of the lower square cylinder portion 50d of the body portion 30. The bottom portion 40 has a corner portion 41, a bottom wall 42, and a dome 43. The corner portion 41 is curved toward the lower side in the axial direction of the PET bottle 1 and the outer side in the radial direction. The substantially flat plate annular bottom wall 42 extends in the direction perpendicular to the body portion 30 and serves as a ground plane for the PET bottle 1. The dome 43 is formed in a hollow hemisphere that curves toward the inside (upper side in the axial direction) of the PET bottle 1. The dome 43 has a function of preventing deformation due to changes in the temperature of the contents of the PET bottle 1 and the internal pressure.

The dome 43 has an inclination with respect to the ground plane. If the angle of inclination θd at the peripheral end of the dome 43 is too small, it becomes difficult to prevent deformation. On the other hand, if the inclination angle θd of the dome 43 is too large, the shapeability of the PET bottle 1 at the time of molding tends to decrease. Therefore, from the viewpoint of effectively dispersing pressure and the like to prevent deformation and improving the shapeability, it is preferable that the inclination angle θd of the dome 43 is 8 ° or more and 18 ° or less.

The dome 43 further has ribs 44. There are four ribs 44 illustrated in FIG. 3, each of which extends radially in a bottom view. The rib 44 has a function of reinforcing the dome 43. The rib 44 can be formed by making the inclination angle different from that of the dome 43. At this time, if the rib 44 is formed at a steeper slope on the peripheral end side of the dome 43, whitening due to overstretching and deterioration of the shapeability of the PET bottle 1 are likely to occur. Therefore, it is preferable that the rib 44 has a gentler inclination on the peripheral end side of the dome 43.

The bottom portion 40 has an annular rising portion 45 extending from the bottom wall 42 located on the outer peripheral side toward the peripheral end of the dome 43, which is larger than the inclination of the dome 43. The rising portion 45 has a function of preventing the bottom portion 40 from protruding from the ground contact surface when a large pressure is applied from the outside of the PET bottle 1. For example, when the PET bottle 1 conveyed in the filling system collides with another PET bottle 1 and pressure is applied and the bottom 40 protrudes, the PET bottle 1 extends in the axial direction. It may cause clogging. This is because the lighter the weight of the PET bottle 1 and the thinner the wall thickness, the greater the need for countermeasures.

If the bottom portion 40 becomes too thin, it becomes difficult to maintain its structure when the pressure inside the PET bottle 1 changes. On the other hand, if the wall thickness is too thick, the weight reduction of the PET bottle 1 is hindered. Therefore, from the viewpoint of maintaining the structure of the bottom 40 while reducing the weight of the PET bottle 1, the wall thickness of the bottom 40 is preferably 0.10 mm or more and 0.35 mm or less.

One of the causes of the bottom portion 40 protruding is that the vicinity of the peripheral end of the dome 43 bends so as to protrude from the ground plane. However, since the rising portion 45 has a large inclination, the deformation direction when pressure is applied is dispersed from the axial direction to the radial direction. Further, the rising portion 45 is stopped in a range that does not protrude from the ground plane even if it is deformed by increasing the axial distance from the ground plane. Then, the strength of the rising portion 45 is increased by discontinuing the inclination with the dome 43. By having these functions, the rising portion 45 effectively prevents the bottom portion 40 from protruding.

Here, if the inclination angle θr of the rising portion 45 is too large, whitening due to overstretching and deterioration of the shapeability of the PET bottle 1 are likely to occur. Therefore, the inclination angle θr of the rising portion 45 is preferably 30 ° or more and 65 ° or less.

Further, if the axial distance H3 of the rising portion 45 is too large, the rising portion 45 becomes a bending point. Therefore, the axial distance H3 of the rising portion 45 is preferably 4 mm or more and 9 mm or less.

Since the PET bottle 1 has the rising portion 45, the degree of freedom in designing the shape of the dome 43 is increased, and the PET bottle 1 does not have to have the rib 44, for example.

Here, the shape maintaining function of the dome 43 can be enhanced by providing a groove or the like extending radially from the dome 43 to the bottom wall 42. However, the PET bottle 1 having a gap in the bottom wall 42 cannot be applied to the method in which the bottom portion 40, which is often used as a filling system, is sucked and conveyed.

On the other hand, the PET bottle 1 in which the bottom wall 42 is formed of a flat surface and does not have a groove or the like recessed toward the upper side in the axial direction can be applied to a method in which the bottom 40 is sucked and conveyed. It has high versatility. Therefore, the PET bottle 1 can maintain the structure of the bottom 40 while having both light weight and high versatility.

The bottom portion 40 is not limited to the example shown in FIG. 3, and may be configured so as to be easily deformed by heat and not easily deformed downward even when positive pressure is applied. As a result, it is possible to prevent the full filling capacity of the PET bottle 1 from increasing and the change in the internal pressure from becoming larger. The dome 43 is designed to remain at least above the ground plane of the PET bottle 1 even if it is deformed by heat. As a result, the bottom portion 40 is prevented from protruding outward (lower side) from the bottom wall 42, and the PET bottle 1 can be prevented from rattling or tipping over.

As described above, the PET bottle 1 has a mouth portion 10, a shoulder portion 20, a body portion 30, and a bottom portion 40, and the body portion 30 includes a plurality of wall portions 31 and adjacent walls in the circumferential direction. The upper square cylinder portion 50u and the lower square cylinder portion 50d, which are composed of the corner portions 32 connecting the portions 31, and the upper square cylinder portion 50u and the lower square cylinder portion 50d are vertically divided and crossed perpendicular to the axial direction. The cylindrical portion 60 has a cylindrical portion 60 having a circular surface, and the cylindrical portion 60 has a constricted portion 61 in which the body portion 30 is narrowed in the radial direction, and the constricted portion 61 is convex outward in the radial direction and axially. It has an extending rib 62, which is configured to maximize the distance from the radial center in any cross section of the constricted portion 61. According to such a configuration, it is possible to provide a large and square PET bottle 1 which has both light weight and high strength against an external force and is easy to hold.

Further, the bottom 40 of the PET bottle 1 has a hollow hemispherical dome 43 that curves toward the inside of the PET bottle 1, and the bottom 40 is directed from the bottom wall 42 located on the outer peripheral side toward the peripheral end of the dome 43. It has an annular rising portion 45 that extends larger than the inclination of the dome 43. According to such a configuration, it is possible to provide a large-sized PET bottle 1 having both light weight and high strength against an external force of the bottom 40.

Further, it has a ridge line 21 extending in the circumferential direction between the shoulder portion 20 and the body portion 30, and the ridge line 21 is located closest to the body portion 30 in the corner portion 32. According to such a configuration, it is possible to provide the PET bottle 1 which has both light weight and high strength at the shoulder portion 20.

The PET bottle 1 according to the present embodiment is not limited by size and can be applied to various sizes. However, a larger bottle is preferable because the effect of the configuration of the PET bottle 1 according to the present embodiment is more exhibited. For example, the internal volume of the PET bottle 1 is preferably 680 ml or more and 2500 ml or less, and more preferably 900 ml to 2000 ml. The total height H1 of the PET bottle 1 may be 190 mm or more and 320 mm or less, and the facing distance D2 of the body portion 30 may be 65 mm or more and 100 mm or less.

Further, the PET bottle 1 according to the present embodiment can be suitably used for a lightweight bottle. The mass of the PET bottle 1 is, for example, 20 g or more and less than 30 g for 1000 ml, and 25 g or more and less than 35 g for 2000 ml. In particular, from the viewpoint of maintaining the strength of the PET bottle 1 while increasing the absorption amount of changes in the internal pressure while having light weight, the value of the ratio of the mass to the internal volume of the PET bottle 1 is 0.0125 g / ml or more. It is preferably 0.0300 g / ml or less.

Examples of the material of the plastic bottle for which PET bottle 1 is exemplified include polyolefins such as high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-vinyl alcohol copolymer, and plants. Various plastics that can be blow-molded, such as polylactic acid, can be used. However, it is preferable that the plastic bottle is mainly composed of polyester such as polyethylene naphthalate, particularly polyethylene terephthalate. In addition, various additives such as a colorant, an ultraviolet absorber, a mold release agent, a lubricant, a nucleating agent, an antioxidant, and an antistatic agent are blended in the above-mentioned resin as long as the quality of the molded product is not impaired. be able to.

As the ethylene terephthalate-based thermoplastic resin constituting the PET bottle 1, the ethylene terephthalate unit occupies most of the ester repeating portion, generally 70 mol% or more, and the glass transition point (Tg) is 50 ° C. or higher and 90 ° C. or higher. It is preferable that the melting point (Tm) is in the range of 200 ° C. or higher and 275 ° C. or lower. As an ethylene terephthalate-based thermoplastic polyester, polyethylene terephthalate is particularly excellent in terms of pressure resistance, etc., but in addition to the ethylene terephthalate unit, it is composed of dibasic acids such as isophthalic acid and naphthalenedicarboxylic acid, and diols such as propylene glycol. Copolymerized polyesters containing a small amount of ester units can also be used.

Polyethylene terephthalate has the highest production volume among thermoplastic synthetic resins. The polyethylene terephthalate resin has various properties such as excellent heat resistance, cold resistance, chemical resistance, and abrasion resistance. Furthermore, polyethylene terephthalate resin has a lower proportion of petroleum in its raw material than other plastics, and can be recycled. As described above, according to the structure containing polyethylene terephthalate as a main component, a material having a large production amount can be used, and various excellent properties thereof can be utilized.

Polyethylene terephthalate is obtained by condensation polymerization of ethylene glycol (ethane-1,2-diol) and purified terephthalic acid. It is preferable that at least one of a germanium compound, a titanium compound, and an aluminum compound is used as the polymerization catalyst of polyethylene terephthalate. By using these catalysts, it is possible to form a container having higher transparency and excellent heat resistance than the antimony compound is used.

A plastic bottle can be produced by blow molding a preform obtained by injection molding the above-mentioned material. Then, by using polyethylene terephthalate as a material, a PET bottle 1 as an example of the plastic bottle according to the present embodiment is produced. Then, the filler is composed of the PET bottle 1 and the liquid to be filled. The filler is manufactured by filling a liquid such as a beverage or a seasoning from the mouth 10 of the PET bottle 1 and sealing it with a lid (not shown) attached to the mouth 10.

Next, the configuration of the plastic bottle according to the modified example will be described in detail. FIG. 5 is a front view showing the PET bottle 100 according to the modified example. The PET bottle 100 has the same configuration as the PET bottle 1 except that it has a rib 162 different from the rib 62 of the PET bottle 1. That is, the PET bottle 100 sequentially has a mouth portion 10, a shoulder portion 20, a body portion 130, and a bottom portion 40 in the axial direction thereof. Further, the body portion 130 divides the upper square cylinder portion 50u and the lower square cylinder portion 50u, the upper square cylinder portion 50u, and the lower square cylinder portion 50d in the axial direction, and has a cross section orthogonal to the axial direction. It has a circular cylindrical portion 160. The cylindrical portion 160 has a constricted portion 161.

The constricted portion 161 has a rib 162 extending in the axial direction. The rib 162 projects toward the outside of the PET bottle 100. The rib 162 has a function as a support for both the axial and radial loads of the PET bottle 100. A plurality of ribs 162 are arranged in the circumferential direction of the constricted portion 161. The constricted portion 161 in which the plurality of ribs 162 are arranged has improved strength and is less likely to be deformed, so that the PET bottle 100 can be easily held. Further, the rib 162 can be hooked on the gripped finger to make it easier to hold the PET bottle 100.

The upper end and the lower end of the constricted portion 161 do not have a configuration corresponding to the upper side 63 and the lower side 64 of the PET bottle 1 connecting the adjacent ribs 162. However, the PET bottle 100 having the rib 162 has both light weight and high strength against an external force, is easy to hold, and has the same effect as the PET bottle 1.

The PET bottle 1 according to the present embodiment may have a configuration different from that described above except for the constricted portion 61 and the constricted portion 161.

Hereinafter, the present disclosure will be described in more detail and concretely with reference to Examples. However, the present disclosure is not limited to the following examples.

<Material and manufacturing method>
[Example 1]
A PET bottle 1 made of 24 g of polyethylene terephthalate and having a full filling capacity of 990 ml as shown in FIG. 1 and the like was used. The maximum body diameter D3 of the constricted portion 61 of the PET bottle 1 was 77.1 mm, and the minimum body diameter D4 was 63.3 mm. PET bottle 1 was filled with 950 ml of water.

In the PET bottle 1 according to the first embodiment, the body portion 30 has an upper square cylinder portion 50u and a lower square cylinder portion 50d in which the body portion 30 includes a plurality of wall portions 31 and corner portions 32 connecting adjacent wall portions 31 in the circumferential direction. The upper square cylinder portion 50u and the lower square cylinder portion 50d are divided in the axial direction, and have a cylindrical portion 60 having a circular cross section orthogonal to the axial direction, and the cylindrical portion 60 has a constricted portion 61. The constricted portion 61 has a rib 62 extending in the axial direction, and the body portion 30 is narrowed in the radial direction. The rib 62 has a distance from the center in the radial direction in any cross section of the constricted portion 61. It had features related to this embodiment such as maximization.

[Comparative Example 1]
Comparative Example 1 was the same as that of Example 1 except that the PET bottle 200 shown in FIG. 6 was used. In the PET bottle 200, the body portion 230 is formed in a square tubular shape having a uniform waist circumference in the axial direction, and the body portion 230 is formed with 13 peripheral grooves 251. The PET bottle 200 did not have a configuration corresponding to the cylindrical portion 60 and the constricted portion 61 of the PET bottle 1. Therefore, the filler according to Comparative Example 1 did not have the characteristics according to the present embodiment.

[Comparative Example 2]
Comparative Example 2 was the same as Comparative Example 1 except that it weighed 28 g. Therefore, the filler according to Comparative Example 2 did not have the characteristics according to the present embodiment.

<Evaluation method>
(Lightweight)
It was determined whether or not the weight reduction could be achieved by the mass of each PET bottle of Example 1, Comparative Example 1, and Comparative Example 2. In determining the weight reduction, a threshold value greater than or less than 24 g was set. Table 1 shows the results of the evaluation of the lightness of each PET bottle, and is indicated by ◯: with lightness and ×: without lightness.

(Buckling strength test)
The buckling strength of PET bottles 1 and 200 in an upright state was measured for each of the fillers of Example 1, Comparative Example 1, and Comparative Example 2. A tester manufactured by AGR, TOP LOAD, was used for measuring the buckling strength. A load was applied from above the mouth portion 10 at a constant speed, and the load at the stage of displacement of 5 mm was defined as the buckling strength. For the determination of buckling strength, a threshold value of 180 N or more or less than 180 N was set. Table 1 shows the results of evaluation of the buckling strength of each filler, and is indicated by ◯: buckling strength and ×: insufficient buckling strength.

(Monitoring survey)
The fillers of Example 1, Comparative Example 1, and Comparative Example 2 were prepared, and the monitors of 100 people in their 20s to 70s were selected to have the best ease of holding. The ones selected for each monitor were counted as one point for each person. Table 1 shows the total score.

(Comprehensive evaluation)
Based on the lightness, buckling strength test, and monitoring survey described above, the PET bottles (fillers) of Example 1, Comparative Example 1, and Comparative Example 2 were comprehensively evaluated. Table 1 shows the results of the comprehensive evaluation. The overall evaluation is indicated by ○: good, ×: no aptitude.

The following points were derived from the above-mentioned examples. The PET bottle 1 (filler) according to Example 1 had sufficient buckling strength while being constructed to be lightweight. And many monitors supported its ease of holding.

On the other hand, in Comparative Example 1, although the weight was reduced, the buckling strength was insufficient. When the weight reduction was slightly insufficient as in Comparative Example 2, the buckling strength was satisfied. The PET bottles 200 of Comparative Example 1 and Comparative Example 2 were inferior in terms of ease of holding because they did not have a constriction.

From the results of the above examples, it was shown that the PET bottle 1 and the filler according to the present embodiment still have sufficient buckling strength and are easy to hold even if the weight is reduced. Therefore, it has been shown that in the present embodiment, it is possible to provide a large and square PET bottle 1 and a filler which have both light weight and high strength against an external force and are easy to hold.

The present disclosure can be suitably used for various plastic bottles filled with a liquid as a content. However, the present disclosure is not limited to the embodiments and examples described above. The plastic bottles of the present disclosure include, for example, various non-sparkling beverages such as water, green tea, oolong tea, black tea, coffee, fruit juice, soft drinks, seasonings such as soy sauce, sauce, and mirin, foods containing cooking oil, and alcoholic beverages. Useful for containing detergents, shampoos, cosmetics, medicines and any other content. In particular, the plastic bottle of the present disclosure is suitable for use in a large bottle whose weight increases due to a large amount of contents because the container is easy to hold.

1,100 PET bottle (plastic bottle)
10 Mouth 20 Shoulder 30, 130 Body 31 Wall 32 Corner 40 Bottom 50u Upper square tube (square tube)
50d Lower square tube (square tube)
60, 160 Cylindrical part 61, 161 Constriction part 62, 162 Rib 65 Panel 70 Articulation groove 75 Articulation groove H2 Constriction part 61, 161 Axial distance

Claims (9)

In a plastic bottle having a mouth, shoulders, body, and bottom sequentially in the axial direction.
The body is
A square tube portion consisting of a plurality of wall portions and corner portions connecting the wall portions adjacent to each other in the circumferential direction.
The square tube portion is divided in the axial direction, and has a cylindrical portion having a circular cross section orthogonal to the axial direction.
The cylindrical portion,
It has a constricted part that is squeezed in the radial direction,
The constricted part is
It has ribs that are convex outward in the radial direction and extend in the axial direction.
The rib
It is configured so that the distance from the center in the radial direction is maximized in any of the cross sections of the constricted portion .
The constricted part is
Plastic bottle according to claim Rukoto to have a panel that the ribs adjacent to the opposite side. The constricted portion has an upper side that is curved toward the upper side and a lower side that is curved toward the lower side.
The panel includes a said rib, said top and plastic bottle according to claim 1, characterized that you have been formed from said lower side. The plastic bottle according to claim 2, wherein the panel is composed of an even number. The plastic bottle according to any one of claims 1 to 3, wherein the maximum body diameter of the cylindrical portion is the same length as the facing distance of the square tubular portion. The plastic according to any one of claims 1 to 4, wherein the square tubular portion and the cylindrical portion are connected via a connecting groove that is recessed in the radial direction and extends in the circumferential direction. Bottle. The plastic bottle according to any one of claims 1 to 5, wherein the rib has a twist in the circumferential direction. The plastic bottle according to any one of claims 1 to 6, wherein the constricted portion has a distance in the axial direction of 55 mm or more and 85 mm or less. The plastic bottle according to any one of claims 1 to 7, wherein the internal volume of the plastic bottle is 680 ml or more and 2500 ml or less. The plastic bottle according to any one of claims 1 to 8.
A filler characterized by being composed of a liquid to be filled.

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